Prophet Muhammad (S) was Unlettered

It is impossible for this Qur’an  to have been produced by a single individual or to have been borrowed by him from other sources, particularly an individual who was unlettered, had not even studied, and had grown up in the degenerate environment of the Arabian peninsula at that time, an environment which was totally alien to science and philosophy.
All historians are unanimous that the Prophet was an unlettered man who had never known books or teachers and never learned how to write. The Qur’an itself addressed him as follows:

“Before this, you did not read any book, nor did you write anything with your hands”. (29:48).
Before the revelation of the Holy Qur’an, the Holy Prophet could neither write with his own hand nor could he read anything written by the others, and this is a fact vouched by one and all of the age of the Holy Prophet.

No opponent in the life time of the Prophet ever raised his voiced to challenge this verse, since for the forty years they stayed with him, they knew he was unlettered. How could have then the prophet authored such an unmatchable book by himself. With this fact in view, it would be sheer absurdity to say that what he delivered as the Qur’an was not the revelation from God, but a reproduction of what he read in the other scriptures and what he wrote, i.e. composed of and memorised.
One may wonder why God, the Almighty commissioned one who was deprived of the capacity of reading or writing as His Apostle? Was not the Prophet supposed to be the most knowledgeable one who was required to teach the people the Book and the wisdom? The answer is that inability to write and read does not mean ignorance, as the Holy Prophet was gifted divine knowledge through miracle, and according to some researchers, the Prophet knew how to read and write not through learning from a teacher but through divine inspiration and miracle.
Infact, the immediate next verse of the Holy Qur’an asserts that the Prophet was granted knowledge:

“Nay! It (Qur’an) is the clear signs in the breast of those who have been granted the knowledge” (29:49).

The Prophet (S) confirmed this by saying: “I am the city of Knowledge and Ali is its door”.  
Whatever the case, the obvious fact remains the same: the one who had never learnt from any human teacher how to read or write, to present this incontestable and universally recognised truth - the Qur’an - which never before was revealed even to the great apostles in the past, could not have possibly been without its source being from above. Unfortunately, there were some who accused the Prophet that he learnt the contents of Qur’an from the others. But this is refuted by the Qur’an eloquently:
“Say (O Muhammad)! The Holy Spirit (Jibriil) has  brought it (Qur’an) down from your Lord with the truth, that it may establish those who believe, and as a guidance and glad tidings unto those who submit (themselves to God). And indeed We know what they say: ‘It is only a man that teaches him’. The tongue of him whom they falsely hint at, is outlandish (foreign language, not eloquent, slang), while this language is Arabic (pure and) plain”. (16:102-103).
However, it is remarkable that such a man who had never studied from any mortal being, was given the most eloquent book: The Glorious Qur’an, and became the standard-bearer of a movement calling for science and free thought. It is said that the mystic object in keeping the Prophet unaware of the art of reading and writing was to help the people to recognise the Qur’an as a Word of God.